A potential well is the region surrounding a local potential energy minimum. Energy captured in a potential well is unable to convert to another type of energy (kinetic energy in the case of a gravitational potential well) because it is captured in the local minimum of a potential well. Therefore, body may not proceed to the global minimum of potential energy, as it would naturally tend to do due to entropy.

Energy may be released from a potential well if sufficient energy is added to the system such that the local minimum is surmounted. In quantum physics, potential energy may escape a potential well without added energy due to the probabilistic characteristics of quantum particles; in these cases a particle may be imagined to teleport through the walls of a potential well.

The graph of a 2D potential energy function is a potential energy surface that can be imagined as the Earth's surface in a landscape of hills and valleys. Then a potential well would be a valley surrounded on all sides with higher terrain, which thus could be filled with water (i.e., be a lake) without any water flowing away toward another, lower minimum (i.e. sea level).

In the case of gravity, the region around a mass is a gravitional potential well, unless the density of the mass is so low that tidal forces from other masses are greater than the gravity of the body itself.

See also

• Graphical representation